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Behaviour of impurity elements during the weathering of ilmenite

Published online by Cambridge University Press:  05 July 2018

I. Grey ,
C. MacRae ,
E. Silvester  and
J. Susini
I. Grey*
Affiliation:
CSIRO Minerals, Bayview Avenue, Clayton, Victoria 3168, Australia
C. MacRae
Affiliation:
CSIRO Minerals, Bayview Avenue, Clayton, Victoria 3168, Australia
E. Silvester
Affiliation:
Latrobe University, Albury-Wodonga Campus, Wodonga, Victoria 3689, Australia
J. Susini
Affiliation:
ESRF, 38043 Grenoble Cedex, France
*
*E-mail: [email protected]
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Abstract

X-ray spectromicroscopy has been applied to the characterization of weathered ilmenite sand samples from Australian localities. X-ray absorption near edge spectroscopy (Xanes) studies were performed at the K-edges of the major elements Fe and Ti and minor impurity elements Mn and Cr. An extended suite of reference samples with crystallite sizes ranging from 1 nm to μm size were measured to establish if the absorption edge characteristics were influenced by crystal size effects. No changes were detected for oxides of Cr3+, Fe3+ or Ti4+, but the mixed Fe2+/Fe3+ oxide, Fe3O4, showed an edge shift to higher energies (by 1.5 eV) in a nanocrystalline sample. The Xanes study of a composite ilmenite grain with an unweathered primary ilmenite core and a highly weathered rim showed that Fe was present as Fe2+ in the core and Fe3+ in the rim whereas Mn was present as Mn2+ in both core and rim. Chromium, which is incorporated into the grains during weathering, is present predominantly as Cr3+, although minor (~15%) Cr6+ also occurs in highly weathered grains. The absorption K-edges of Fe3+ and Mn2+ are shifted markedly (by 2–3 eV) to higher energies in titanate phases relative to the binary oxides Fe2O3 and MnO.

Keywords

weatheringilmeniteAustraliatitanium
Type
Research Article
Information
Mineralogical Magazine , Volume 69 , Issue 4 , August 2005 , pp. 437 - 446
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2005

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References

Buerge, I.J. and Hug, S.J. (1999) Influence of mineral surfaces on chromium (VI) reduction by iron (II). Environmental Science and Technology, 33, 4285–4291.CrossRefGoogle Scholar
Ellis, B.A., Harris, H.R. and Hudson, R.L. (1994) In Proceedings of 11th Industrial Minerals International Conference (Griffiths, J.B., editor). Industrial Minerals Division of Metals Bulletin, Surrey, UK, pp. 102–108.Google Scholar
Farges, F., Brown, G.E. Jr. and Rehr, J.J. (1997) Ti K-edge XANES studies of Ti coordination and disorder in oxide compounds: Comparison between theory and experiment. Physics Review B, 56, 1809–1819.CrossRefGoogle Scholar
Frost, M.T., Grey, I.E., Harrowfield, I.R. and Mason, K. (1983) The dependence of alumina and silica contents on the extent of alteration of weathered ilmenites from Western Australia. Mineralogical Magazine, 47, 201–208.CrossRefGoogle Scholar
Grey, I.E. and Li, C. (2003) Hydroxylian pseudomtile derived from picroilmenite in the Murray Basin, southeastern Australia. Mineralogical Magazine, 67, 733–747.CrossRefGoogle Scholar
Grey, I.E., Li, C. and Ness, T. (1998) Nonstoichiometric Li-Pseudobrookite (ss) in the Li2O-Fe2O3-TiO2 system. Journal of Solid State Chemistry, 141, 221–228.CrossRefGoogle Scholar
Nicholson, T.A., Grey, I.E. and Brown, C.J. (1999) Production of synthetic rutile by low temperature reduction of ilmenite. Australian patent AU 199936760, 25 July, 1999.Google Scholar
Qu, S., Yang, H., Ren, D., Kan, S., Zou, G., Li, D. and Li, M. (1999) Magnetite nanoparticles prepared by precipitation from partially reduced ferric chloride aqueous solutions. Journal of Colloid and Interface Science, 215, 190–192.CrossRefGoogle ScholarPubMed
Susini, J., Salome, M., Fayard, B., Ortega, R. and Kaulich, B. (2002) The scanning X-ray microprobe at the ESRF ‘X-ray Microscopy’ beamline. Surface Review and Letters, 9, 203–211.CrossRefGoogle Scholar
Uozumi, T., Okada, K., Kotani, A., Durmeyer, O., Kappler, J.P., Beaurepaire, E. and Parlebas, J.C. (1992) Experimental and theoretical investigation of the pre-peaks at the Ti K-edge absorption spectra in TiO2 . Europhysics Letters, 18, 85–90.CrossRefGoogle Scholar